Yeah I foolishly paid for 500 Mb/s but the only things I ever get over even 200 Mb/s for in the UK are Steam downloads (and speed tests). Everything else seems to be roughly throttled at that rate.
Yeah the default is they supply a "modem" with a regular ethernet port, so a familiar config to someone coming from cable or DSL, but inside it's a QSFP that you can move to your own equipment if you want.